package com.xiaoyu.security;

public class DES {

	private int[] encryptKeys = new int[32];
	private int[] decryptKeys = new int[32];

	private int[] tempInts = new int[2];

	public DES() {

	}

	// Constructor, byte-array key.
	public DES(byte[] key) {
		if (key.length == 7) {
			byte[] key8 = new byte[8];
			makeSMBKey(key, key8);
			setKey(key8);
		} else {
			setKey(key);
		}
	}

	public static void makeSMBKey(byte[] key7, byte[] key8) {

		int i;

		key8[0] = (byte) ((key7[0] >> 1) & 0xff);
		key8[1] = (byte) ((((key7[0] & 0x01) << 6) | (((key7[1] & 0xff) >> 2) & 0xff)) & 0xff);
		key8[2] = (byte) ((((key7[1] & 0x03) << 5) | (((key7[2] & 0xff) >> 3) & 0xff)) & 0xff);
		key8[3] = (byte) ((((key7[2] & 0x07) << 4) | (((key7[3] & 0xff) >> 4) & 0xff)) & 0xff);
		key8[4] = (byte) ((((key7[3] & 0x0F) << 3) | (((key7[4] & 0xff) >> 5) & 0xff)) & 0xff);
		key8[5] = (byte) ((((key7[4] & 0x1F) << 2) | (((key7[5] & 0xff) >> 6) & 0xff)) & 0xff);
		key8[6] = (byte) ((((key7[5] & 0x3F) << 1) | (((key7[6] & 0xff) >> 7) & 0xff)) & 0xff);
		key8[7] = (byte) (key7[6] & 0x7F);
		for (i = 0; i < 8; i++) {
			key8[i] = (byte) (key8[i] << 1);
		}
	}

	// / Set the key.
	public void setKey(byte[] key) {

		// CHECK PAROTY TBD
		deskey(key, true, encryptKeys);
		deskey(key, false, decryptKeys);
	}

	// Turn an 8-byte key into internal keys.
	private void deskey(byte[] keyBlock, boolean encrypting, int[] KnL) {

		int i, j, l, m, n;
		int[] pc1m = new int[56];
		int[] pcr = new int[56];
		int[] kn = new int[32];

		for (j = 0; j < 56; ++j) {
			l = pc1[j];
			m = l & 07;
			pc1m[j] = ((keyBlock[l >>> 3] & bytebit[m]) != 0) ? 1 : 0;
		}

		for (i = 0; i < 16; ++i) {

			if (encrypting)
				m = i << 1;
			else
				m = (15 - i) << 1;
			n = m + 1;
			kn[m] = kn[n] = 0;
			for (j = 0; j < 28; ++j) {
				l = j + totrot[i];
				if (l < 28)
					pcr[j] = pc1m[l];
				else
					pcr[j] = pc1m[l - 28];
			}
			for (j = 28; j < 56; ++j) {
				l = j + totrot[i];
				if (l < 56)
					pcr[j] = pc1m[l];
				else
					pcr[j] = pc1m[l - 28];
			}
			for (j = 0; j < 24; ++j) {
				if (pcr[pc2[j]] != 0)
					kn[m] |= bigbyte[j];
				if (pcr[pc2[j + 24]] != 0)
					kn[n] |= bigbyte[j];
			}
		}
		cookey(kn, KnL);
	}

	private void cookey(int[] raw, int KnL[]) {
		int raw0, raw1;
		int rawi, KnLi;
		int i;

		for (i = 0, rawi = 0, KnLi = 0; i < 16; ++i) {
			raw0 = raw[rawi++];
			raw1 = raw[rawi++];
			KnL[KnLi] = (raw0 & 0x00fc0000) << 6;
			KnL[KnLi] |= (raw0 & 0x00000fc0) << 10;
			KnL[KnLi] |= (raw1 & 0x00fc0000) >>> 10;
			KnL[KnLi] |= (raw1 & 0x00000fc0) >>> 6;
			++KnLi;
			KnL[KnLi] = (raw0 & 0x0003f000) << 12;
			KnL[KnLi] |= (raw0 & 0x0000003f) << 16;
			KnL[KnLi] |= (raw1 & 0x0003f000) >>> 4;
			KnL[KnLi] |= (raw1 & 0x0000003f);
			++KnLi;
		}
	}

	// / Encrypt a block of eight bytes.
	private void encrypt(byte[] clearText, int clearOff, byte[] cipherText,
			int cipherOff) {

		squashBytesToInts(clearText, clearOff, tempInts, 0, 2);
		des(tempInts, tempInts, encryptKeys);
		spreadIntsToBytes(tempInts, 0, cipherText, cipherOff, 2);
	}

	// / Decrypt a block of eight bytes.
	private void decrypt(byte[] cipherText, int cipherOff, byte[] clearText,
			int clearOff) {

		squashBytesToInts(cipherText, cipherOff, tempInts, 0, 2);
		des(tempInts, tempInts, decryptKeys);
		spreadIntsToBytes(tempInts, 0, clearText, clearOff, 2);
	}

	// The DES function.
	private void des(int[] inInts, int[] outInts, int[] keys) {

		int fval, work, right, leftt;
		int round;
		int keysi = 0;

		leftt = inInts[0];
		right = inInts[1];

		work = ((leftt >>> 4) ^ right) & 0x0f0f0f0f;
		right ^= work;
		leftt ^= (work << 4);

		work = ((leftt >>> 16) ^ right) & 0x0000ffff;
		right ^= work;
		leftt ^= (work << 16);

		work = ((right >>> 2) ^ leftt) & 0x33333333;
		leftt ^= work;
		right ^= (work << 2);

		work = ((right >>> 8) ^ leftt) & 0x00ff00ff;
		leftt ^= work;
		right ^= (work << 8);
		right = (right << 1) | ((right >>> 31) & 1);

		work = (leftt ^ right) & 0xaaaaaaaa;
		leftt ^= work;
		right ^= work;
		leftt = (leftt << 1) | ((leftt >>> 31) & 1);

		for (round = 0; round < 8; ++round) {
			work = (right << 28) | (right >>> 4);
			work ^= keys[keysi++];
			fval = SP7[work & 0x0000003f];
			fval |= SP5[(work >>> 8) & 0x0000003f];
			fval |= SP3[(work >>> 16) & 0x0000003f];
			fval |= SP1[(work >>> 24) & 0x0000003f];
			work = right ^ keys[keysi++];
			fval |= SP8[work & 0x0000003f];
			fval |= SP6[(work >>> 8) & 0x0000003f];
			fval |= SP4[(work >>> 16) & 0x0000003f];
			fval |= SP2[(work >>> 24) & 0x0000003f];
			leftt ^= fval;
			work = (leftt << 28) | (leftt >>> 4);
			work ^= keys[keysi++];
			fval = SP7[work & 0x0000003f];
			fval |= SP5[(work >>> 8) & 0x0000003f];
			fval |= SP3[(work >>> 16) & 0x0000003f];
			fval |= SP1[(work >>> 24) & 0x0000003f];
			work = leftt ^ keys[keysi++];
			fval |= SP8[work & 0x0000003f];
			fval |= SP6[(work >>> 8) & 0x0000003f];
			fval |= SP4[(work >>> 16) & 0x0000003f];
			fval |= SP2[(work >>> 24) & 0x0000003f];
			right ^= fval;
		}

		right = (right << 31) | (right >>> 1);
		work = (leftt ^ right) & 0xaaaaaaaa;
		leftt ^= work;
		right ^= work;
		leftt = (leftt << 31) | (leftt >>> 1);
		work = ((leftt >>> 8) ^ right) & 0x00ff00ff;
		right ^= work;
		leftt ^= (work << 8);
		work = ((leftt >>> 2) ^ right) & 0x33333333;
		right ^= work;
		leftt ^= (work << 2);
		work = ((right >>> 16) ^ leftt) & 0x0000ffff;
		leftt ^= work;
		right ^= (work << 16);
		work = ((right >>> 4) ^ leftt) & 0x0f0f0f0f;
		leftt ^= work;
		right ^= (work << 4);
		outInts[0] = right;
		outInts[1] = leftt;
	}

	// / Encrypt a block of bytes.
	public void encrypt(byte[] clearText, byte[] cipherText) {
		encrypt(clearText, 0, cipherText, 0);
	}

	// / Decrypt a block of bytes.
	public void decrypt(byte[] cipherText, byte[] clearText) {

		decrypt(cipherText, 0, clearText, 0);
	}

	/**
	 * encrypts an array where the length must be a multiple of 8
	 */
	public byte[] encrypt(byte[] clearText) {

		int length = clearText.length;

		if (length % 8 != 0) {
			System.out.println("Array must be a multiple of 8");
			return null;
		}

		byte[] cipherText = new byte[length];
		int count = length / 8;

		for (int i = 0; i < count; i++)
			encrypt(clearText, i * 8, cipherText, i * 8);

		return cipherText;
	}

	/**
	 * decrypts an array where the length must be a multiple of 8
	 */
	public byte[] decrypt(byte[] cipherText) {

		int length = cipherText.length;

		if (length % 8 != 0) {
			System.out.println("Array must be a multiple of 8");
			return null;
		}

		byte[] clearText = new byte[length];
		int count = length / 8;

		for (int i = 0; i < count; i++)
			encrypt(cipherText, i * 8, clearText, i * 8);

		return clearText;
	}

	// Tables, permutations, S-boxes, etc.

	private static byte[] bytebit = { (byte) 0x80, (byte) 0x40, (byte) 0x20,
			(byte) 0x10, (byte) 0x08, (byte) 0x04, (byte) 0x02, (byte) 0x01 };
	private static int[] bigbyte = { 0x800000, 0x400000, 0x200000, 0x100000,
			0x080000, 0x040000, 0x020000, 0x010000, 0x008000, 0x004000,
			0x002000, 0x001000, 0x000800, 0x000400, 0x000200, 0x000100,
			0x000080, 0x000040, 0x000020, 0x000010, 0x000008, 0x000004,
			0x000002, 0x000001 };
	private static byte[] pc1 = { (byte) 56, (byte) 48, (byte) 40, (byte) 32,
			(byte) 24, (byte) 16, (byte) 8, (byte) 0, (byte) 57, (byte) 49,
			(byte) 41, (byte) 33, (byte) 25, (byte) 17, (byte) 9, (byte) 1,
			(byte) 58, (byte) 50, (byte) 42, (byte) 34, (byte) 26, (byte) 18,
			(byte) 10, (byte) 2, (byte) 59, (byte) 51, (byte) 43, (byte) 35,
			(byte) 62, (byte) 54, (byte) 46, (byte) 38, (byte) 30, (byte) 22,
			(byte) 14, (byte) 6, (byte) 61, (byte) 53, (byte) 45, (byte) 37,
			(byte) 29, (byte) 21, (byte) 13, (byte) 5, (byte) 60, (byte) 52,
			(byte) 44, (byte) 36, (byte) 28, (byte) 20, (byte) 12, (byte) 4,
			(byte) 27, (byte) 19, (byte) 11, (byte) 3 };
	private static int[] totrot = { 1, 2, 4, 6, 8, 10, 12, 14, 15, 17, 19, 21,
			23, 25, 27, 28 };

	private static byte[] pc2 = { (byte) 13, (byte) 16, (byte) 10, (byte) 23,
			(byte) 0, (byte) 4, (byte) 2, (byte) 27, (byte) 14, (byte) 5,
			(byte) 20, (byte) 9, (byte) 22, (byte) 18, (byte) 11, (byte) 3,
			(byte) 25, (byte) 7, (byte) 15, (byte) 6, (byte) 26, (byte) 19,
			(byte) 12, (byte) 1, (byte) 40, (byte) 51, (byte) 30, (byte) 36,
			(byte) 46, (byte) 54, (byte) 29, (byte) 39, (byte) 50, (byte) 44,
			(byte) 32, (byte) 47, (byte) 43, (byte) 48, (byte) 38, (byte) 55,
			(byte) 33, (byte) 52, (byte) 45, (byte) 41, (byte) 49, (byte) 35,
			(byte) 28, (byte) 31, };

	private static int[] SP1 = { 0x01010400, 0x00000000, 0x00010000,
			0x01010404, 0x01010004, 0x00010404, 0x00000004, 0x00010000,
			0x00000400, 0x01010400, 0x01010404, 0x00000400, 0x01000404,
			0x01010004, 0x01000000, 0x00000004, 0x00000404, 0x01000400,
			0x01000400, 0x00010400, 0x00010400, 0x01010000, 0x01010000,
			0x01000404, 0x00010004, 0x01000004, 0x01000004, 0x00010004,
			0x00000000, 0x00000404, 0x00010404, 0x01000000, 0x00010000,
			0x01010404, 0x00000004, 0x01010000, 0x01010400, 0x01000000,
			0x01000000, 0x00000400, 0x01010004, 0x00010000, 0x00010400,
			0x01000004, 0x00000400, 0x00000004, 0x01000404, 0x00010404,
			0x01010404, 0x00010004, 0x01010000, 0x01000404, 0x01000004,
			0x00000404, 0x00010404, 0x01010400, 0x00000404, 0x01000400,
			0x01000400, 0x00000000, 0x00010004, 0x00010400, 0x00000000,
			0x01010004 };
	private static int[] SP2 = { 0x80108020, 0x80008000, 0x00008000,
			0x00108020, 0x00100000, 0x00000020, 0x80100020, 0x80008020,
			0x80000020, 0x80108020, 0x80108000, 0x80000000, 0x80008000,
			0x00100000, 0x00000020, 0x80100020, 0x00108000, 0x00100020,
			0x80008020, 0x00000000, 0x80000000, 0x00008000, 0x00108020,
			0x80100000, 0x00100020, 0x80000020, 0x00000000, 0x00108000,
			0x00008020, 0x80108000, 0x80100000, 0x00008020, 0x00000000,
			0x00108020, 0x80100020, 0x00100000, 0x80008020, 0x80100000,
			0x80108000, 0x00008000, 0x80100000, 0x80008000, 0x00000020,
			0x80108020, 0x00108020, 0x00000020, 0x00008000, 0x80000000,
			0x00008020, 0x80108000, 0x00100000, 0x80000020, 0x00100020,
			0x80008020, 0x80000020, 0x00100020, 0x00108000, 0x00000000,
			0x80008000, 0x00008020, 0x80000000, 0x80100020, 0x80108020,
			0x00108000 };
	private static int[] SP3 = { 0x00000208, 0x08020200, 0x00000000,
			0x08020008, 0x08000200, 0x00000000, 0x00020208, 0x08000200,
			0x00020008, 0x08000008, 0x08000008, 0x00020000, 0x08020208,
			0x00020008, 0x08020000, 0x00000208, 0x08000000, 0x00000008,
			0x08020200, 0x00000200, 0x00020200, 0x08020000, 0x08020008,
			0x00020208, 0x08000208, 0x00020200, 0x00020000, 0x08000208,
			0x00000008, 0x08020208, 0x00000200, 0x08000000, 0x08020200,
			0x08000000, 0x00020008, 0x00000208, 0x00020000, 0x08020200,
			0x08000200, 0x00000000, 0x00000200, 0x00020008, 0x08020208,
			0x08000200, 0x08000008, 0x00000200, 0x00000000, 0x08020008,
			0x08000208, 0x00020000, 0x08000000, 0x08020208, 0x00000008,
			0x00020208, 0x00020200, 0x08000008, 0x08020000, 0x08000208,
			0x00000208, 0x08020000, 0x00020208, 0x00000008, 0x08020008,
			0x00020200 };
	private static int[] SP4 = { 0x00802001, 0x00002081, 0x00002081,
			0x00000080, 0x00802080, 0x00800081, 0x00800001, 0x00002001,
			0x00000000, 0x00802000, 0x00802000, 0x00802081, 0x00000081,
			0x00000000, 0x00800080, 0x00800001, 0x00000001, 0x00002000,
			0x00800000, 0x00802001, 0x00000080, 0x00800000, 0x00002001,
			0x00002080, 0x00800081, 0x00000001, 0x00002080, 0x00800080,
			0x00002000, 0x00802080, 0x00802081, 0x00000081, 0x00800080,
			0x00800001, 0x00802000, 0x00802081, 0x00000081, 0x00000000,
			0x00000000, 0x00802000, 0x00002080, 0x00800080, 0x00800081,
			0x00000001, 0x00802001, 0x00002081, 0x00002081, 0x00000080,
			0x00802081, 0x00000081, 0x00000001, 0x00002000, 0x00800001,
			0x00002001, 0x00802080, 0x00800081, 0x00002001, 0x00002080,
			0x00800000, 0x00802001, 0x00000080, 0x00800000, 0x00002000,
			0x00802080 };
	private static int[] SP5 = { 0x00000100, 0x02080100, 0x02080000,
			0x42000100, 0x00080000, 0x00000100, 0x40000000, 0x02080000,
			0x40080100, 0x00080000, 0x02000100, 0x40080100, 0x42000100,
			0x42080000, 0x00080100, 0x40000000, 0x02000000, 0x40080000,
			0x40080000, 0x00000000, 0x40000100, 0x42080100, 0x42080100,
			0x02000100, 0x42080000, 0x40000100, 0x00000000, 0x42000000,
			0x02080100, 0x02000000, 0x42000000, 0x00080100, 0x00080000,
			0x42000100, 0x00000100, 0x02000000, 0x40000000, 0x02080000,
			0x42000100, 0x40080100, 0x02000100, 0x40000000, 0x42080000,
			0x02080100, 0x40080100, 0x00000100, 0x02000000, 0x42080000,
			0x42080100, 0x00080100, 0x42000000, 0x42080100, 0x02080000,
			0x00000000, 0x40080000, 0x42000000, 0x00080100, 0x02000100,
			0x40000100, 0x00080000, 0x00000000, 0x40080000, 0x02080100,
			0x40000100 };
	private static int[] SP6 = { 0x20000010, 0x20400000, 0x00004000,
			0x20404010, 0x20400000, 0x00000010, 0x20404010, 0x00400000,
			0x20004000, 0x00404010, 0x00400000, 0x20000010, 0x00400010,
			0x20004000, 0x20000000, 0x00004010, 0x00000000, 0x00400010,
			0x20004010, 0x00004000, 0x00404000, 0x20004010, 0x00000010,
			0x20400010, 0x20400010, 0x00000000, 0x00404010, 0x20404000,
			0x00004010, 0x00404000, 0x20404000, 0x20000000, 0x20004000,
			0x00000010, 0x20400010, 0x00404000, 0x20404010, 0x00400000,
			0x00004010, 0x20000010, 0x00400000, 0x20004000, 0x20000000,
			0x00004010, 0x20000010, 0x20404010, 0x00404000, 0x20400000,
			0x00404010, 0x20404000, 0x00000000, 0x20400010, 0x00000010,
			0x00004000, 0x20400000, 0x00404010, 0x00004000, 0x00400010,
			0x20004010, 0x00000000, 0x20404000, 0x20000000, 0x00400010,
			0x20004010 };
	private static int[] SP7 = { 0x00200000, 0x04200002, 0x04000802,
			0x00000000, 0x00000800, 0x04000802, 0x00200802, 0x04200800,
			0x04200802, 0x00200000, 0x00000000, 0x04000002, 0x00000002,
			0x04000000, 0x04200002, 0x00000802, 0x04000800, 0x00200802,
			0x00200002, 0x04000800, 0x04000002, 0x04200000, 0x04200800,
			0x00200002, 0x04200000, 0x00000800, 0x00000802, 0x04200802,
			0x00200800, 0x00000002, 0x04000000, 0x00200800, 0x04000000,
			0x00200800, 0x00200000, 0x04000802, 0x04000802, 0x04200002,
			0x04200002, 0x00000002, 0x00200002, 0x04000000, 0x04000800,
			0x00200000, 0x04200800, 0x00000802, 0x00200802, 0x04200800,
			0x00000802, 0x04000002, 0x04200802, 0x04200000, 0x00200800,
			0x00000000, 0x00000002, 0x04200802, 0x00000000, 0x00200802,
			0x04200000, 0x00000800, 0x04000002, 0x04000800, 0x00000800,
			0x00200002 };
	private static int[] SP8 = { 0x10001040, 0x00001000, 0x00040000,
			0x10041040, 0x10000000, 0x10001040, 0x00000040, 0x10000000,
			0x00040040, 0x10040000, 0x10041040, 0x00041000, 0x10041000,
			0x00041040, 0x00001000, 0x00000040, 0x10040000, 0x10000040,
			0x10001000, 0x00001040, 0x00041000, 0x00040040, 0x10040040,
			0x10041000, 0x00001040, 0x00000000, 0x00000000, 0x10040040,
			0x10000040, 0x10001000, 0x00041040, 0x00040000, 0x00041040,
			0x00040000, 0x10041000, 0x00001000, 0x00000040, 0x10040040,
			0x00001000, 0x00041040, 0x10001000, 0x00000040, 0x10000040,
			0x10040000, 0x10040040, 0x10000000, 0x00040000, 0x10001040,
			0x00000000, 0x10041040, 0x00040040, 0x10000040, 0x10040000,
			0x10001000, 0x10001040, 0x00000000, 0x10041040, 0x00041000,
			0x00041000, 0x00001040, 0x00001040, 0x00040040, 0x10000000,
			0x10041000 };

	// / Squash bytes down to ints.
	public static void squashBytesToInts(byte[] inBytes, int inOff,
			int[] outInts, int outOff, int intLen) {

		for (int i = 0; i < intLen; ++i)
			outInts[outOff + i] = ((inBytes[inOff + i * 4] & 0xff) << 24)
					| ((inBytes[inOff + i * 4 + 1] & 0xff) << 16)
					| ((inBytes[inOff + i * 4 + 2] & 0xff) << 8)
					| (inBytes[inOff + i * 4 + 3] & 0xff);
	}

	// / Spread ints into bytes.
	public static void spreadIntsToBytes(int[] inInts, int inOff,
			byte[] outBytes, int outOff, int intLen) {

		for (int i = 0; i < intLen; ++i) {

			outBytes[outOff + i * 4] = (byte) (inInts[inOff + i] >>> 24);
			outBytes[outOff + i * 4 + 1] = (byte) (inInts[inOff + i] >>> 16);
			outBytes[outOff + i * 4 + 2] = (byte) (inInts[inOff + i] >>> 8);
			outBytes[outOff + i * 4 + 3] = (byte) inInts[inOff + i];
		}
	}
}
